DESCRIPTION OF THE FIGURES. 157 



transfer of their constituents, consisting of the three vessels 

 connected by amianthus. 



Fig. 7. Is one of the wire-stands employed by M. De Luc 

 in his dissection of the galvanic pile. 



Fig. 8. Is the apparatus for receiving in separate vessel* 

 the gases which are evolved by the action of galvanism upon 

 water. The two small jars have metallic wires inserted at 

 their upper end, one of which is connected with the positive, 

 and the other with the negative extremity of the pile. They 

 are filled with water and inverted in the same fluid ; and the 

 ends of the wires are so situated, that the gas disengaged from 

 them rises to the top of the jar. 



Fig. 9. Represents the lower limbs of a frog, lying on a 

 plate of metal, while another kind of metal is placed in con- 

 tact with the spinal marrow ; these two metals are then con- 

 nected by a conducting body, and the muscles of the legs are 

 thrown into convulsions. 



Fig. 10. Are the agate cups, connected by amianthus, 

 employed by Sir H. Davy in the decomposition of water; 

 and Fig. 11, are the gold cones in the same set of ex- 

 periments. 



Fig. 12. Represents the apparatus in which the gases dis- 

 engaged from water may be reconverted into water by the 

 electric spark. 



PLATE II. 



Figs. 1, 2, 3, 4. The dissected pile employed by De Luc, 

 to illustrate the mode of its action. The shaded part re- 

 presents the moistened cloths, and the letters C and Z the 

 copper and zinc plates respectively. In Fig. 1, the pile 

 is continuous, in its usual form ; Fig. 2, is the first dissection; 

 Fig. 3, the second; and Fig. 4, the third. 



Fig. 5. Is the author's numerical illustration of the effect 

 of the pile ; the letters point out the nature of the substances, 

 and the figures indicate the increase of power which the 

 electricity acquires by passing along the instrument. 



Fig. 6. Is an experiment of Mr. Singer's, which is supposed 

 to disprove the hypothesis of electric energies. In this appa- 

 ratus each wire will have its ends in the opposite states of 

 electricity, one positive and the othej 1 negative. 



